Etiglena and Trachelomonas. 19 



of the various conditions of this species, to indicate the un- 

 certainty of specific characters. 



Besides the green, granular condition, there is a form also 

 green but having numerous large, round, or oval, and clear 

 cells, very closely resembling starch-cells when viewed in water. 

 After a time, these cells appear to be set free, but I have 

 watched them for weeks and found no change in them. 



From the green condition the color becomes bright red, and 

 between the two extremes forms can be found partly red and 

 green, the red color occupying more or less of the central por- 

 tion. 



In the red forms we find variations precisely the counter- 

 part of those already described in the green; the granular 

 and the large celled forms, with or without cilia. Either the 

 green or the red forms may lose their cilia, become spherical 

 and surrounded with a thick coat, outside of which may be 

 seen a layer of gelatinous substance which, if the forms are 

 numerous, may unite them into large, fiat sheets. Within the 

 thick and unyielding coat the form may exhibit amoeboid 

 movements, may be seen to revolve, and finally subdivide 

 into two parts which finally emerge by the rupture of the 

 shell as two independent forms, similar to the original. 



President Hyatt had observed that a certain Trachelo7nonas 

 was at times very abundant in the water which contained the 

 Euglenae, and he strongly suspected that the two organisms 

 were closely related in their life-history. The same idea had 

 occurred to me, and on September 27th I was pleased to 

 notice the following occurrence: In examining a collection 

 from the Port Morris pond, I found many specimens of active 

 Trachelomonas with which were associated green Euglenae. 

 Among the rest were a number of broken shells of Trachelo- 

 monas (whether ruptured naturally or by the pressure of the 

 cover-glass I could not tell), but within one of them there was 

 a bright green body exactly resembling the free Euglenae, 

 alternately contracting and elongating and protruding part 

 of its body through the fracture of the shell, moving the two 

 cilia vigorously all the time. Soon the cilia became quiet, the 

 green organism issued from the shell, leaving the cilia attached, 

 and crawled about precisely like the ordinary Euglenae with- 

 out cilia. By an accident this particular form was lost and 

 could not be distinguished from the others. 



